The present invention relates to the crimping of textile fibers.
A conventional technique for crimping textile fibers, especially synthetic fibers, involves advancing the fibers, or tow, into a stuffer box which resists the rate of egress of the tow from the box. The tow is advanced into the box by a pair of motor-driven crimper rolls which define therebetween a nip through which the tow is advanced. In order to restrain the tow from wandering out of its intended travel path while passing through the nip, a pair of cheek plates, or crimper disks, are positioned on opposite ends of the rolls. The cheek plates include front faces which are pushed against the ends of the crimper rolls as the rolls rotate and are thus subject to considerable wear during operation.
This wear results from frictional contact between the cheek plates and the ends of the crimper rolls, and as the result of contact between the tow and the cheek plates at the center of the cheek plates. As regards the latter type of wear, the tow tends to be forced laterally outwardly (i.e., parallel to the axes of the crimper rolls), as it is forced through the nip and thus rubs against the center of the cheek plate faces. That rubbing contact damages the tow by an abrasion and fusing action and also wears the cheek plate face. As the worn area becomes enlarged, there is formed a gap between the cheek plate face and the nip, whereupon tow fibers may become wedged into that gap to produce further wearing of the cheek plate face and damage to the fiber by a cutting and tearing action. Eventually, the wear becomes substantial enough to require that the cheek plates be replaced. It should be noted that the wearing of the cheek plate faces occurs notwithstanding the fact that the faces are lubricated somewhat by finish liquid normally carried by the tow.
One manner of dealing with the problem of cheek plate wear involves the well-known technique of intermittently rotating the cheek plates. This does not reduce the rate of wear which occurs, but rather distributes the wear more evenly around the cheek plate face to increase the useful life of the cheek plate.
Another proposal involves the practice of lubricating the cheek plates by pumping a lubricating liquid through holes in the cheek plates as disclosed, for example, in Baken U.S. Pat. No. 3,662,439 issued May 16, 1972. The holes are spaced from the center of the cheek plate and are supplied with lubricant by means of channels formed in a holder which carries the cheek plate. That lubricant augments the lubrication provided by the finish carried by the tow. While such a proposal results in an increase in the lubrication of certain peripheral regions of the cheek plate face, other regions, such as at the center, do not have the lubrication increased appreciably. Generally speaking, the lubrication of that center region depends to a great extent upon the finish liquid carried by the tow. However, as the tow enters the nip, much of the finish liquid is squeezed from the tow; hence, the lubrication carried by the tow which contacts the cheek plate faces is significantly diminished.
It will thus be appreciated that significant room for improvement remains as regards the reduction of the wear of cheek plates.
It is, therefore, an object of the present invention to minimize or obviate problems of the type discussed above.
Another object is to reduce the wear occurring in the vicinity where the cheek plate face opposes the nip between the crimper rolls.
An additional object is to reduce cheek plate wear in a manner which is readily adaptable to rotary cheek plates as well as stationary cheek plates.